The finding that RIOK1 was up-regulated at the protein level in PCa cells extends the number of cancer types with proved RIOK1 overexpression.10, 11, 12,14,15 In a study by Huang et al13 in breast cancer, proliferation was inhibited and apoptosis was induced with knockdown of RIOK1, consistent with the present results in PCa after RIOK1 inhibition. Here, RIOK1 is linked to cancer.